/* ── Site chrome: the shared top nav + footer of every marketing page ──────
   Markup lives in scripts/site-partials/site-nav.html and site-footer.html and is
   synced into the pages by scripts/site-chrome.mjs (`--check` runs in
   local-ci, so a page that drifts turns the gate red).

   Origin = the landing page's own .nav / .footer (public/landing.html keeps
   its inline copy because its header also carries the invite banner, the tab
   router and the i18n select). Geometry, colours and breakpoints here are a
   1:1 mirror of it: 64px bar, 1fr auto 1fr grid, solid near-black after 72px
   of scroll. Change one → change the other.

   Every selector is scoped under .bm-chrome so it out-ranks the older
   single-class .nav/.brand/.links/.footer rules in seo-common.css (still
   linked by /mac) without touching that file. ── */
:root { --nav-h: 64px; }

.nav.bm-chrome {
  position: sticky;
  top: 0;
  z-index: 30;
  background: transparent;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  border-bottom: 1px solid transparent;
  transition: background 0.25s ease, border-color 0.25s ease, backdrop-filter 0.25s ease;
}
.nav.bm-chrome.scrolled {
  background: rgba(0, 0, 0, 0.86);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom-color: rgba(255, 255, 255, 0.08);
}
.nav.bm-chrome .wrap {
  width: 100%;
  max-width: none;
  margin: 0;
  height: var(--nav-h);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  justify-content: normal;
  gap: 20px;
  padding: 0 32px;
}
.nav.bm-chrome .brand {
  display: inline;
  color: #ffffff;
  font-family: inherit;
  font-size: 17px;
  font-weight: 650;
  line-height: 1;
  letter-spacing: 0;
  text-decoration: none;
  justify-self: start;
  white-space: nowrap;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.35);
  cursor: pointer;
  transition: opacity 0.18s ease;
}
.nav.bm-chrome .brand:hover { opacity: 0.78; }
.nav.bm-chrome .links {
  display: flex;
  align-items: center;
  justify-self: center;
  gap: 2px;
  color: rgba(255, 255, 255, 0.92);
  font-size: 14px;
  font-weight: 500;
  line-height: 23px;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.35);
}
.nav.bm-chrome .links a {
  color: inherit;
  text-decoration: none;
  border-radius: 8px;
  padding: 6px 10px;
  transition: color 0.18s ease, background 0.18s ease;
  white-space: nowrap;
}
.nav.bm-chrome .links a:hover,
.nav.bm-chrome .links a[aria-current="page"] {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.08);
}
.nav.bm-chrome .nav-right {
  display: flex;
  align-items: center;
  gap: 10px;
  justify-self: end;
}
.nav.bm-chrome .nav-contact,
.nav.bm-chrome .nav-login {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 34px;
  padding: 6px 16px;
  border-radius: 999px;
  font-family: inherit;
  font-size: 13px;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  transition: opacity 0.18s ease, background 0.18s ease, border-color 0.18s ease;
}
.nav.bm-chrome .nav-contact {
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.42);
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}
.nav.bm-chrome .nav-contact:hover {
  background: rgba(255, 255, 255, 0.18);
  border-color: rgba(255, 255, 255, 0.66);
}
.nav.bm-chrome .nav-login {
  color: #0d0d0d;
  border: 1px solid #ffffff;
  background: #ffffff;
}
.nav.bm-chrome .nav-login:hover { opacity: 0.82; }
.nav.bm-chrome .lang-toggle {
  min-height: 34px;
  padding: 6px 30px 6px 14px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.42);
  background-color: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  color: #ffffff;
  font-family: inherit;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' fill='none'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%23ffffff' stroke-width='1.5' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  transition: background-color 0.18s ease, border-color 0.18s ease;
}
.nav.bm-chrome .lang-toggle:hover {
  background-color: rgba(255, 255, 255, 0.18);
  border-color: rgba(255, 255, 255, 0.66);
}
.nav.bm-chrome .lang-toggle option { background: #ffffff; color: #0d0d0d; }

/* ── Footer ── */
.footer.bm-chrome {
  padding: 48px 0 56px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  background: var(--bm-ground, #020409);
  font-family: inherit;
  line-height: 1.5;
  text-align: left;
}
.footer.bm-chrome .wrap {
  width: min(1152px, calc(100% - 64px));
  max-width: none;
  height: auto;
  margin: 0 auto;
  padding: 0;
  display: block;
}
.footer.bm-chrome .footer-grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(4, minmax(0, 1fr));
  gap: 16px;
}
.footer.bm-chrome h2 {
  margin: 0;
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: rgba(248, 250, 252, 0.55);
}
.footer.bm-chrome .brand {
  display: inline-block;
  color: #f8fafc;
  font-family: inherit;
  font-size: 17px;
  font-weight: 650;
  line-height: 1;
  text-decoration: none;
}
.footer.bm-chrome a,
.footer.bm-chrome p,
.footer.bm-chrome li {
  color: rgba(248, 250, 252, 0.62);
  text-decoration: none;
  font-size: 13px;
  line-height: 1.9;
  margin: 0;
}
.footer.bm-chrome a:hover { color: #ffffff; }
.footer.bm-chrome ul { list-style: none; margin: 8px 0 0; padding: 0; }
.footer.bm-chrome .footer-tagline { margin-top: 8px; }
.footer.bm-chrome .copyright {
  margin-top: 28px;
  padding-top: 0;
  border-top: 0;
  color: rgba(248, 250, 252, 0.48);
  font-size: 12px;
}

/* ── Breakpoints: same two as landing. On phones the links drop under the
   brand row as a second strip (so --nav-h grows) and Contact folds away. ── */
@media (max-width: 980px) {
  :root { --nav-h: 92px; }
  .nav.bm-chrome .wrap {
    display: flex;
    flex-wrap: wrap;
    align-content: center;
    gap: 6px 20px;
    padding: 0 20px;
  }
  .nav.bm-chrome .brand { order: 1; margin-right: auto; }
  .nav.bm-chrome .nav-right { order: 2; }
  .nav.bm-chrome .links {
    order: 3;
    flex-basis: 100%;
    justify-content: flex-start;
    margin-left: -10px; /* cancels the first link's own left padding */
    gap: 4px;
  }
  .nav.bm-chrome .nav-contact { display: none; }
}
@media (max-width: 640px) {
  :root { --nav-h: 82px; }
  .nav.bm-chrome .wrap { gap: 4px 16px; padding: 0 16px; }
  .nav.bm-chrome .links { font-size: 15px; margin-left: -12px; }
  .nav.bm-chrome .links a { padding: 6px 12px; }
  .nav.bm-chrome .brand { font-size: 16px; }
  .nav.bm-chrome .nav-right { gap: 6px; }
  .nav.bm-chrome .nav-login { padding: 6px 12px; font-size: 12px; min-height: 30px; }
  .nav.bm-chrome .lang-toggle { min-height: 30px; font-size: 12px; }
  .footer.bm-chrome { padding: 36px 0 40px; }
  .footer.bm-chrome .wrap { width: calc(100% - 32px); }
  .footer.bm-chrome .footer-grid { grid-template-columns: 1fr 1fr; gap: 22px 14px; }
  .footer.bm-chrome .footer-grid > div:first-child { grid-column: 1 / -1; }
}

/* Keyboard (2026-09-20 批 7): one focus ring for every control on the pages
   that wear the shared chrome. landing.html carries its own copy. */
:where(a, button, select, summary, [tabindex]):focus-visible { outline: 2px solid #60a5fa; outline-offset: 3px; }